/*
 * Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package com.sun.org.apache.bcel.internal.classfile;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache BCEL" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
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 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache BCEL", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
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 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

import com.sun.org.apache.bcel.internal.Constants;
import java.io.*;

/**
 * This class represents the type of a local variable or item on stack
 * used in the StackMap entries.
 *
 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 * @see     StackMapEntry
 * @see     StackMap
 * @see     Constants
 */
public final class StackMapType implements Cloneable {
    private byte type;
    private int index = -1; // Index to CONSTANT_Class or offset
    private ConstantPool constant_pool;

    /**
     * Construct object from file stream.
     * @param file Input stream
     * @throws IOException
     */
    StackMapType(DataInputStream file, ConstantPool constant_pool) throws IOException {
        this(file.readByte(), -1, constant_pool);

        if (hasIndex())
            setIndex(file.readShort());

        setConstantPool(constant_pool);
    }

    /**
     * @param type type tag as defined in the Constants interface
     * @param index index to constant pool, or byte code offset
     */
    public StackMapType(byte type, int index, ConstantPool constant_pool) {
        setType(type);
        setIndex(index);
        setConstantPool(constant_pool);
    }

    public void setType(byte t) {
        if ((t < Constants.ITEM_Bogus) || (t > Constants.ITEM_NewObject))
            throw new RuntimeException("Illegal type for StackMapType: " + t);
        type = t;
    }

    public byte getType() {
        return type;
    }

    public void setIndex(int t) {
        index = t;
    }

    /** @return index to constant pool if type == ITEM_Object, or offset
     * in byte code, if type == ITEM_NewObject, and -1 otherwise
     */
    public int getIndex() {
        return index;
    }

    /**
     * Dump type entries to file.
     *
     * @param file Output file stream
     * @throws IOException
     */
    public final void dump(DataOutputStream file) throws IOException {
        file.writeByte(type);
        if (hasIndex())
            file.writeShort(getIndex());
    }

    /** @return true, if type is either ITEM_Object or ITEM_NewObject
     */
    public final boolean hasIndex() {
        return ((type == Constants.ITEM_Object) || (type == Constants.ITEM_NewObject));
    }

    private String printIndex() {
        if (type == Constants.ITEM_Object)
            return ", class=" + constant_pool.constantToString(index, Constants.CONSTANT_Class);
        else if (type == Constants.ITEM_NewObject)
            return ", offset=" + index;
        else
            return "";
    }

    /**
     * @return String representation
     */
    public final String toString() {
        return "(type=" + Constants.ITEM_NAMES[type] + printIndex() + ")";
    }

    /**
     * @return deep copy of this object
     */
    public StackMapType copy() {
        try {
            return (StackMapType) clone();
        } catch (CloneNotSupportedException e) {
        }

        return null;
    }

    /**
     * @return Constant pool used by this object.
     */
    public final ConstantPool getConstantPool() {
        return constant_pool;
    }

    /**
     * @param constant_pool Constant pool to be used for this object.
     */
    public final void setConstantPool(ConstantPool constant_pool) {
        this.constant_pool = constant_pool;
    }
}
